Inbred maize line NP2171

ABSTRACT

The invention relates to an inbred maize line, designated NP2171, the plants and seeds of inbred maize line NP2171, and methods for producing a hybrid maize pland and seed by crossing a plant of the inbred line 2171 with itself or with another maize plant.

FIELD OF THE INVENTION

This invention is in the field of maize breeding, specifically relatingto an inbred maize line designated NP2171.

BACKGROUND OF THE INVENTION

The goal of plant breeding is to combine in a single variety or hybridvarious desirable traits. For field crops, these traits may includeresistance to diseases and insects, tolerance to heat and drought,reducing the time to crop maturity, greater yield, and better agronomicquality. With mechanical harvesting of many crops, uniformity of plantcharacteristics such as germination and stand establishment, growthrate, maturity, and plant and ear height, is important.

Field crops are bred through techniques that take advantage of theplant's method of pollination. A plant is self-pollinated if pollen fromone flower is transferred to the same or another flower of the sameplant. A plant is cross-pollinated if the pollen comes from a flower ona different plant. Plants that have been self-pollinated and selectedfor type for many generations become homozygous at almost all gene lociand produce a uniform population of true breeding progeny. A crossbetween two different homozygous lines produces a uniform population ofhybrid plants that may be heterozygous for many gene loci. A cross oftwo plants each heterozygous at a number of gene loci will produce apopulation of hybrid plants that differ genetically and will not beuniform.

Maize (Zea mays L.), often referred to as corn in the United States, canbe bred by both self-pollination and cross-pollination techniques. Maizehas separate male and female flowers on the same plant, located on thetassel and the ear, respectively. Natural pollination occurs in maizewhen wind blows pollen from the tassels to the silks that protrude fromthe tops of the ears.

A reliable method of controlling male fertility in plants offers theopportunity for improved plant breeding. This is especially true fordevelopment of maize hybrids, which relies upon some sort of malesterility system. There are several options for controlling malefertility available to breeders, such as: manual or mechanicalemasculation (or detasseling), cytoplasmic male sterility, genetic malesterility, gametocides and the like.

Hybrid maize seed is typically produced by a male sterility systemincorporating manual or mechanical detasseling. Alternate strips of twomaize inbreds are planted in a field, and the pollen-bearing tassels areremoved from one of the inbreds (female). Providing that there issufficient isolation from sources of foreign maize pollen, the ears ofthe detasseled inbred will be fertilized only from the other inbred(male) and the resulting seed is therefore hybrid and will form hybridplants.

The laborious, and occasionally unreliable, detasseling process can beavoided by using cytoplasmic male-sterile (CMS) inbreds. Plants of a CMSinbred are male sterile as a result of factors resulting from thecytoplasmic, as opposed to the nuclear, genome. Thus, thischaracteristic is inherited exclusively through the female parent inmaize plants, since only the female provides cytoplasm to the fertilizedseed. CMS plants are fertilized with pollen from another inbred that isnot male-sterile. Pollen from the second inbred may or may notcontribute genes that make the hybrid plants male-fertile. Seed fromdetasseled fertile maize and CMS produced seed of the same hybrid can beblended to insure that adequate pollen loads are available forfertilization when the hybrid plants are grown.

There are several methods of conferring genetic male sterilityavailable, such as multiple mutant genes at separate locations withinthe genome that confer male sterility, as disclosed in U.S. Pat. Nos.4,654,465 and 4,727,219 and chromosomal translocations as described inU.S. Pat. Nos. 3,861,709 and 3,710,511, the disclosures of which arespecifically incorporated herein by reference. There are many othermethods of conferring genetic male sterility in the art, each with itsown benefits and drawbacks. These methods use a variety of approachessuch as delivering into the plant a gene encoding a cytotoxic substanceassociated with a male tissue specific promoter or an antisense systemin which a gene critical to fertility is identified and an antisense tothat gene is inserted in the plant (EPO 89/3010153.8 and WO 90/08828).

Another system useful in controlling male sterility makes use ofgametocides. Gametocides are not a genetic system, but rather a topicalapplication of chemicals. These chemicals affect cells that are criticalto male fertility. The application of these chemicals affects fertilityin the plants only for the growing season in which the gametocide isapplied (see Carlson, Glenn R., U.S. Pat. No. 4,936,904, which isincorporated herein by reference). Application of the gametocide, timingof the application and genotype specificity often limit the usefulnessof the approach.

The use of male sterile inbreds is but one factor in the production ofmaize hybrids. The development of maize hybrids requires, in general,the development of homozygous inbred lines, the crossing of these lines,and the evaluation of the crosses. Pedigree breeding and recurrentselection breeding methods are used to develop inbred lines frombreeding populations. Breeding programs combine the genetic backgroundsfrom two or more inbred lines or various other germplasm sources intobreeding pools from which new inbred lines are developed by selfing andselection of desired phenotypes. The new inbreds are crossed with otherinbred lines and the hybrids from these crosses are evaluated todetermine which of those have commercial potential. Plant breeding andhybrid development are expensive and time-consuming processes.

Pedigree breeding starts with the crossing of two genotypes, each ofwhich may have one or more desirable characteristics that is lacking inthe other or which complements the other. If the two original parents donot provide all the desired characteristics, other sources can beincluded in the breeding population. In the pedigree method, superiorplants are selfed and selected in successive generations. In thesucceeding generations the heterozygous condition gives way tohomogeneous lines as a result of self-pollination and selection.Typically in the pedigree method of breeding five or more generations ofselfing and selection is practiced: F1 to F2; F3 to F4; F4 to F5, etc.

A single cross maize hybrid results from the cross of two inbred lines,each of which has a genotype that complements the genotype of the other.The hybrid progeny of the first generation is designated F1. In thedevelopment of commercial hybrids only the F1 hybrid plants are sought.Preferred F1 hybrids are more vigorous than their inbred parents. Thishybrid vigor, or heterosis, can be manifested in many polygenic traits,including increased vegetative growth and increased yield.

The development of a maize hybrid involves three steps: (1) theselection of plants from various germplasm pools for initial breedingcrosses; (2) the selfing of the selected plants from the breedingcrosses for several generations to produce a series of inbred lines,which, although different from each other, breed true and are highlyuniform; and (3) crossing the selected inbred lines with differentinbred lines to produce the hybrid progeny (F1). During the inbreedingprocess in maize, the vigor of the lines decreases. Vigor is restoredwhen two different inbred lines are crossed to produce the hybridprogeny (F1). An important consequence of the homozygosity andhomogeneity of the inbred lines is that the hybrid between a definedpair of inbreds will always be the same. Once the inbreds that give asuperior hybrid have been identified, the hybrid seed can be reproducedindefinitely as long as the homogeneity of the inbred parents ismaintained.

A single cross hybrid is produced when two inbred lines are crossed toproduce the F1 progeny. A double cross hybrid is produced from fourinbred lines crossed in pairs (A×B and C×D) and then the two F1 hybridsare crossed again (A×B)×(C×D). Much of the hybrid vigor exhibited by F1hybrids is lost in the next generation (F2). Consequently, seed fromhybrids is not used for planting stock.

Hybrid seed production requires elimination or inactivation of pollenproduced by the female parent. Incomplete removal or inactivation of thepollen provides the potential for self-pollination. This inadvertentlyself-pollinated seed may be unintentionally harvested and packaged withhybrid seed. Once the seed is planted, it is possible to identify andselect these self-pollinated plants. These self-pollinated plants willbe genetically equivalent to the female inbred line used to produce thehybrid. Typically these self-pollinated plants can be identified andselected due to their decreased vigor. Female selfs are identified bytheir less vigorous appearance for vegetative and/or reproductivecharacteristics, including shorter plant height, small ear size, ear andkernel shape, cob color, or other characteristics.

Identification of these self-pollinated lines can also be accomplishedthrough molecular marker analyses. See, “The Identification of FemaleSelfs in Hybrid Maize: A Comparison Using Electrophoresis andMorphology”, Smith, J. S. C. and Wych, R. D., Seed Science andTechnology 14, pp. 1-8 (1995), the disclosure of which is expresslyincorporated herein by reference. Through these technologies, thehomozygosity of the self-pollinated line can be verified by analyzingallelic composition at various loci along the genome. Those methodsallow for rapid identification of the invention disclosed herein. Seealso, “Identification of Atypical Plants in Hybrid Maize Seed byPostcontrol and Electrophoresis” Sarca, V. et al., Probleme de GeneticaTeoritca si Aplicata Vol. 20 (1) p. 29-42.

As is readily apparent to one skilled in the art, the foregoing are onlytwo of the various ways by which the inbred can be obtained by thoselooking to use the germplasm. Other means are available, and the aboveexamples are illustrative only.

Maize is an important and valuable field crop. Thus, a continuing goalof plant breeders is to develop high-yielding maize hybrids that areagronomically sound based on stable inbred lines. The reasons for thisgoal are obvious: to maximize the amount of grain produced with theinputs used and minimize susceptibility of the crop to pests andenvironmental stresses. To accomplish this goal, the maize breeder mustselect and develop superior inbred parental lines for producing hybrids.This requires identification and selection of genetically uniqueindividuals that occur in a segregating population. The segregatingpopulation is the result of a combination of crossover events plus theindependent assortment of specific combinations of alleles at many geneloci that results in specific genotypes. The probability of selectingany one individual with a specific genotype from a breeding cross isinfinitesimal due to the large number of segregating genes and theunlimited recombinations of these genes, some of which may be closelylinked. However, the genetic variation among individual progeny of abreeding cross allows for the identification of rare and valuable newgenotypes. These new genotypes are neither predictable nor incrementalin value, but rather the result of manifested genetic variation combinedwith selection methods, environments and the actions of the breeder.Thus, even if the entire genotypes of the parents of the breeding crosswere characterized and a desired genotype known, only a few, if any,individuals having the desired genotype may be found in a largesegregating F2 population. Typically, however, neither the genotypes ofthe breeding cross parents nor the desired genotype to be selected isknown in any detail. In addition, it is not known how the desiredgenotype would react with the environment. This genotype by environmentinteraction is an important, yet unpredictable, factor in plantbreeding. A breeder of ordinary skill in the art cannot predict thegenotype, how that genotype will interact with various climaticconditions or the resulting phenotypes of the developing lines, exceptperhaps in a very broad and general fashion. A breeder of ordinary skillin the art would also be unable to recreate the same line twice from thevery same original parents, as the breeder is unable to direct how thegenomes combine or how they will interact with the environmentalconditions. This unpredictability results in the expenditure of largeamounts of research resources in the development of a superior new maizeinbred line.

SUMMARY OF THE INVENTION

According to the invention, there is provided a novel inbred maize line,designated NP2171. This invention thus relates to the seeds of inbredmaize line NP2171, to the plants of inbred maize line NP2171, and tomethods for producing a maize plant by crossing the inbred line NP2171with itself or another maize line. This invention further relates tohybrid maize seeds and plants produced by crossing the inbred lineNP2171 with another maize line.

The invention is also directed to inbred maize line NP2171 into whichone or more specific, single gene traits, for example transgenes, havebeen introgressed from another maize line. Preferably, the resultingline has essentially all of the morphological and physiologicalcharacteristics of inbred maize line of NP2171, in addition to the oneor more specific, single gene traits introgressed into the inbred,preferably the resulting line has all of the morphological andphysiological characteristics of inbred maize line of NP2171, inaddition to the one or more specific, single gene traits introgressedinto the inbred. The invention also relates to seeds of an inbred maizeline NP2171 into which one or more specific, single gene traits havebeen introgressed and to plants of an inbred maize line NP2171 intowhich one or more specific, single gene traits have been introgressed.The invention further relates to methods for producing a maize plant bycrossing plants of an inbred maize line NP2171 into which one or morespecific, single gene traits have been introgressed with themselves orwith another maize line. The invention also further relates to hybridmaize seeds and plants produced by crossing plants of an inbred maizeline NP2171 into which one or more specific, single gene traits havebeen introgressed with another maize line. The invention is alsodirected to a method of producing inbreds comprising planting acollection of hybrid seed, growing plants from the collection,identifying inbreds among the hybrid plants, selecting the inbred plantsand controlling their pollination to preserve their homozygosity.

DEFINITIONS

In the description and examples that follow, a number of terms are usedherein. In order to provide a clear and consistent understanding of thespecification and claims, including the scope to be given such terms,the following definitions are provided. Below are the descriptors usedin the data tables included herein. All linear measurements are incentimeters unless otherwise noted.

Heat units (Max Temp(<=86 deg. F.)+Min Temp(>=50 deg. F.))/2-50

EMRGN Final number of plants per plot

KRTP Kernel type: 1. sweet 2. dent 3. flint 4. flour 5. pop 6.ornamental 7. pipecorn 8. other

ERTLP % Root lodging (before anthesis)

GRNSP % Brittle snapping (before anthesis)

TBANN Tassel branch angle of 2nd primary lateral branch (at anthesis)

LSPUR Leaf sheath pubescence of second leaf above the ear (at anthesis)1-9 (1=none)

ANGBN Angle between stalk and 2nd leaf above the ear (at anthesis)

CR2L Color of 2nd leaf above the ear (at anthesis)

GLCR Glume Color

GLCB Glume color bars perpendicular to their veins (glume bands): 1.absent 2. present

ANTC Anther color

PLQUR Pollen Shed: 0-9 (0=male sterile)

HU1PN Heat units to 10% pollen shed

HUPSN Heat units to 50% pollen shed

SLKC Silk color

HU5SN Heat units to 50% silk

SLK5N Days to 50% silk in adapted zone

HU9PN Heat units to 90% pollen shed

HUPLN Heat units from 10% to 90% pollen shed

DA19 Days from 10% to 90% pollen shed

LAERN Number of leaves above the top ear node

MLWVR Leaf marginal waves: 1-9 (1=none)

LFLCR Leaf longitudinal creases: 1-9 (1=none)

ERLLN Length of ear leaf at the top ear node

ERLWN Width of ear leaf at the top ear node at the widest point

PLHCN Plant height to tassel tip

ERHCN Plant height to the top ear node

LTEIN Length of the internode between the ear node and the node above

LTASN Length of the tassel from top leaf collar to tassel tip

LTBRN Number of lateral tassel branches that originate from the centralspike

EARPN Number of ears per stalk

APBRR Anthocyanin pigment of brace roots: 1.absent 2.faint 3.moderate4.dark

TILLN Number of tillers per plant

HSKC Husk color 25 days after 50% silk (fresh)

HSKD Husk color 65 days after 50% silk (dry)

HSKTR Husk tightness 65 days after 50% silk: 1-9 (1=loose)

HSKCR Husk extension: 1. short (ear exposed) 2. medium (8 cm) 3. long(8-10 cm) 4. very long (>10 cm)

HEPSR Position of ear 65 days after 50% silk: 1.upright 2.horizontal3.pendent

STGRP % Staygreen at maturity

DPOPN % dropped ears 65 days after anthesis

LRTRN % root lodging 65 days after anthesis

HU25 Heat units to 25% grain moisture

HUSG Heat units from 50% silk to 25% grain moisture in adapted zone

DSGM Days from 50% silk to 25% grain moisture in adapted zone

SHLNN Shank length

ERLNN Ear length

ERDIN Diameter of the ear at the midpoint

EWGTN Weight of a husked ear (grams)

KRRWR Kernel rows: 1.indistinct 2.distinct

KRNAR Kernel row alignment: 1. straight 2. slightly curved 3. curved

ETAPR Ear taper: 1. slight 2. average 3. extreme

KRRWN Number of kernel rows

COBC Cob color

COBDN Diameter of the cob at the midpoint

KRTP Endosperm type: 1. sweet 2. extra sweet 3. normal 4. high amylose5. waxy 6. high protein 7. high lysine 8. super sweet 9. high oil 10.other

KRCL Hard endosperm color

ALEC Aleurone color

ALCP Aleurone color pattern: 1. homozygous 2. segregating

KRLNN Kernel length (mm)

KRWDN Kernel width (mm)

KRDPN Kernel thickness (mm)

K100N 100 kernel weight (grams)

KRPRN % round kernels on 13/64 slotted screen

GRLSR Grey leaf spot severity rating; 1=resistent, 9=susceptible.

INTLR Intactness rating of plants at time of harvest; 1=all foliageintact, 9=all plants broken below the ear.

LRTLP Percentage of plants lodged, leaning >30 degrees from vertical,but unbroken at harvest.

MST_P Percent grain moisture at harvest.

SCLBR Southern corn leaf blight severity rating; 1=resistent,9=susceptible.

STKLP Percentage of plants with stalks broken below the ear at time ofharvest.

YBUAN Grain yield expressed as bushels per acre adjusted to 15.5% grainmoisture.

STBWR Stewart Bacterial Wilt

ERLNN Ear Length

CRSTR Common Rust Rating

GRQUR Grain Quality

PLTAR Plant Appearance

HUBLN Heat Units to Black Layer

TSTWN Test Weight in LBS/BU

PSTSP Push Test for Stalk/Root Quality on Erect Plants

ERGRR Early Growth: 6+Leaf Stage

DETAILED DESCRIPTION OF THE INVENTION

Inbred maize lines are typically developed for use in the production ofhybrid maize lines. Inbred maize lines need to be highly homogeneous,homozygous and reproducible to be useful as parents of commercialhybrids. There are many analytical methods available to determine thehomozygotic and phenotypic stability of these inbred lines.

The oldest and most traditional method of analysis is the observation ofphenotypic traits. The data is usually collected in field experimentsover the life of the maize plants to be examined. Phenotypiccharacteristics most often observed are for traits associated with plantmorphology, ear and kernel morphology, insect and disease resistance,maturity, and yield.

In addition to phenotypic observations, the genotype of a plant can alsobe examined. There are many laboratory-based techniques available forthe analysis, comparison and characterization of plant genotype; amongthese are Isozyme Electrophoresis, Restriction Fragment LengthPolymorphisms (RFLPs), Randomly Amplified Polymorphic DNAs (RAPDs),Arbitrarily Primed Polymerase Chain Reaction (AP-PCR), DNA AmplificationFingerprinting (DAF), Sequence Characterized Amplified Regions (SCARs),Amplified Fragment Length Polymorphisms (AFLPs), and Simple SequenceRepeats (SSRs) which are also referred to as Microsatellites.

Some of the most widely used of these laboratory techniques are IsozymeElectrophoresis and RFLPs as discussed in Lee, M., “Inbred Lines ofMaize and Their Molecular Markers,” The Maize Handbook,(Springer-Verlag, New York, Inc. 1994, at 423-432). IsozymeElectrophoresis is a useful tool in determining genetic composition,although it has relatively low number of available markers and the lownumber of allelic variants among maize inbreds. RFLPs have the advantageof revealing an exceptionally high degree of allelic variation in maizeand the number of available markers is almost limitless. Maize RFLPlinkage maps have been rapidly constructed and widely implemented ingenetic studies. One such study is described in Boppenmaier, et al.,“Comparisons among strains of inbreds for RFLPs”, Maize GeneticsCooperative Newsletter, 65:1991, pg. 90. This study used 101 RFLPmarkers to analyze the patterns of 2 to 3 different deposits each offive different inbred lines. The inbred lines had been selfed from 9 to12 times before being adopted into 2 to 3 different breeding programs.It was results from these 2 to 3 different breeding programs thatsupplied the different deposits for analysis. These five lines weremaintained in the separate breeding programs by selfing or sibbing androgueing off-type plants for an additional one to eight generations.After the RFLP analysis was completed, it was determined the five linesshowed 0-2% residual heterozygosity. Although this was a relativelysmall study, it can be seen using RFLPs that the lines had been highlyhomozygous prior to the separate strain maintenance.

The production of hybrid maize lines typically comprises planting inpollinating proximity seeds of, for example, inbred maize line NP2171and of a different inbred parent maize plant, cultivating the seeds ofinbred maize line NP2171 and of said different inbred parent maize plantinto plants that bear flowers, emasculating the male flowers of inbredmaize line NP2171 or the male flowers of said different inbred parentmaize plant to produce an emasculated maize plant, allowingcross-pollination to occur between inbred maize line NP2171 and saiddifferent inbred parent maize plant and harvesting seeds produced onsaid emasculated maize plant. The harvested seed are grown to producehybrid maize plants.

Inbred maize line NP2171 can be crossed to inbred maize lines of variousheterotic group (see e.g. Hallauer et al. (1988) in Corn and CornImprovement, Sprague et al, eds, chapter 8, pages 463-564) for theproduction of hybrid maize lines.

TABLE I VARIETY DESCRIPTION INFORMATION Inbred maize line NP2171 iscompared to inbred A619 INBRED NP2171 INBRED A619 Heat Heat Days UnitsDays Units MATURITY From emergence to 50% of plants in silk 63 1261.5 681359.8 From emergence to 50% of plants in pollen 63 1266.3 65 1280.1From 10% to 90% pollen shed 003 0080.3 004 0130.0 Sample Sample Std DevSize Std Dev Size PLANT cm Plant Height (to tassel tip) 171.7 13.87 10185.2 23.44 12 cm Ear Height (to base of top ear node) 53.9 6.19 10 45.510.0 12 cm Length of Top Ear Internodenode 12.4 3.77 12 13.8 4.52 12Average Number of Tillers 0.2 0.27 8 0.1 0.22 8 Average Number of Earsper Stalk 1.5 0.47 12 1.0 0.16 12 1 = Absent 2 = Faint 3 = Moderate 4 =Dark 3 2 Sample Sample Std Dev Size Std Dev Size LEAF Cm Width of EarNode Leaf 007.5 2.08 12 008.1 2.46 12 cm Length of Ear Node Leaf 076.927.04 10 062.5 20.38 10 Number of leaves above top ear 5 0.3 12 05 0.1612 Degrees Leaf Angle (measure from 2nd 42 18.36 12 47 13.71 12 leafabove ear at Anthesis to stalk above leaf) Leaf Color 03 (Munsell code 02 (Munsell code  5GY 4/4) 5GY 5/4) Leaf Sheath Pubescence (Rate onscale 4 2 from 1 = none to 9 = like peach fuzz) Marginal Waves (Rate onscale from 4 5 1 = none to 9 = many) Longitudinal Creases (Rate on scalefrom 4 4 1 = none to 9 = many) TASSEL Number of Primary Lateral Branches6 0.92 12 8 1.43 12 Branch Angle from Central Spike 49 21.76 12 47 8.4112 Cm Tassel Length (from top leaf collar to 35.8 10.56 12 35.1 10.64 12tassel tip) Pollen Shed (Rate on scale from 0 = male 5 6 sterile to 9 =heavy shed) Anther Color 17 (Munsell code  05 (Munsell code  5rp 5/4)2.5GY 8/6) Glume Color 26 (Munsell code) 26 (Munsell code) Bar Glumes(Glume Bands): 1 = Absent 2 2 2 = Present EAR (Unhusked Data) Silk Color(3 days after emergence) 26 (Munsell code) 05 (Munsell code  2.5GY 8/8)Fresh Husk Color (25 days after 50% (Munsell code) (Munsell code)silking) Dry Husk Color (65 days after 50% 22 (Munsell code  22 (Munsellcode  silking) 2.5y 8/4) 2.5y 8/4) Position of Ear at Dry Husk Stage: 22 1 = Upright 2 = Horizontal 3 = Pendent Husk Tightness (Rate on scalefrom 1 = very 3 4 loose to 9 = very tight) Husk Extension (at harvest):1 = Short (ears 2 2 exposed) 2 = Medium (<8 cm) 3 = Long (8-10 cm beyondear tip) 4 = Very long (>10 cm) Sample Sample Std Dev Size Std Dev SizeEAR (Husked Ear Data) Cm Ear Length 12.9 0.99 12 13.9 2.16 12 mm EarDiameter at mid-point 40.1 2.73 12 41.0 2.53 11 gm Ear Weight 100.3 21.612 88.2 32.78 11 Number of Kernel Rows 13 1.12 12 14 1.4 11 Kernel Rows:1 = Indistinct 2 = Distinct 2 2 Row Alignment: 1 = Straight 2 = Slightly2 1 Curved 3 = Spiral cm Shank Length 9.5 2.45 12 9.5 3.07 12 Ear Taper:1 = Slight 2 = Average 1 2 3 = Extreme Sample Sample Std Dev Size StdDev Size KERNEL (Dried) mm Kernel Length 10.2 0.52 12 10.0 0.84 11 mmKernel Width 8.3 0.41 12 8.3 1.08 11 mm Kernel Thickness 4.5 0.77 12 4.51.14 11 % Round Kernels (Shape Grade) 44.5 30.48 12 63.3 31.23 11Aleurone Color Pattern: 1 = Homozygous 1 1 2 = Segregating AleuroneColor 26 (Munsell code) 19 (Munsell code) Hard Endosperm Color 06(Munsell code  06 (Munsell code  2.5y 8/10) 2.5Y */10) Endosperm Type: 1= Sweet (su1) 2 = Extra 3 3 Sweet (sh2) 3 = Normal Starch Gm Weight per100 Kernels (unsized 30.1 29.2 sample) Sample Sample Std Dev Size StdDev Size COB mm Cob Diameter at mid-point 25.0 1.56 12 27.1 1.23 11 CobColor 19 (Munsell code) 19 (Munsell code) DISEASE RESISTANCE (1 = mostsusceptible to 9 = most resistant) Eye Spot (Kabatiella zeae) 4 4Northern Leaf Blight 3 Mixed 4 Mixed Inoc. Inoc. Gray Leaf Spot 5 3Common Rust 7 6 INSECT RESISTANCE (Rate from 1 = most susceptible to 9 =most resistant) European Corn Borer (Osstrinia nubilalis) 7 5 1^(st)Generation (Typically Whorl Leaf Feeding) 2^(nd) Generation Corn Borer 44 AGRONOMIC TRAITS Stay Green (at 65 days after anthesis) 9 7 (rate onscale from 1 = worst to 9 = excellent) % Dropped Ears (at 65 days afteranthesis) 0 0 % Pre-anthesis Brittle snapping 1 1 % Pre-anthesis RootLodging 0 1 % Post-anthesis Root Lodging (at 65 days 0 0 after anthesis)Kg/ha Yield of Inbred Per Se (at 12-13% 2358 3399 grain moisture)

In interpreting the foregoing color designations, reference may be madeto the Munsell Glossy Book of Color, a standard color reference. Colorcodes: 1. light green, 2. medium green, 3. dark green, 4. very darkgreen, 5. green-yellow, 6. pale yellow, 7. yellow, 8. yellow-orange, 9.salmon, 10. pink-orange, 11. pink, 12. light red, 13 cherry red, 14.red, 15. red and white, 16. pale purple, 17. purple, 18. colorless, 19.white, 20. white capped, 21. buff, 22. tan, 23. brown, 24. bronze, 25.variegated, 26. other.

Other comments to help interpret data are as follows:

1) Heat Units per day were calculated using the standard formula:HU={MaxTemp (86)+Min Temp (50)]/2-50.

2) Large standard deviations are probably due to environmental factorsat each individual location where the variety was observed. Since thevarieties reported in this exhibit are inbreds, the response to theenvironment is probably more pronounced than a hybrid or a combinationof these inbred lines. Any stress at specific times during the growingseason could influence results.

3) The glume color of NP2171 is 05 or green-yellow (Munsell value 2.5GY7/6) and/or 05 or green-yellow with 16 or pale purple shade (Munsellvalue 5RP 6/4).

4) The glume color of A619 is 05 or green-yellow (Munsell value 5GY 7/6)and a small percentage 05 or green-yellow with 16 or pale purple(Munsell value 5RP 6/4) shade.

5) The silk color of NP2171 is green-yellow or 2.5GY 8/8 with palepurple shaded ends.

6) There are some purple tips to the NP2171 glume.

7) The glume color bars (glume band) of NP2171 are shaded purple.

8) Some of the glume color bars (glume band) of A619 are shaded palepurple.

9) Aleurone color of NP2171 appears to have a slight reddish shade.

10) Disease and Insect Ratings for NP2171 were recorded in 1997, 1998,and 2000.

11) Disease and Insect Ratings for A619 were recorded in 1995, 1996, and2000.

Comparisons of the two varieties were conducted in “side-by-side” trialsin 1998, 1999, and 2000 at three different sites. The trial locationswere London, Ontario, Canada, Stanton, Minn. and Janesville, Wis. Thetrials had two replications at each site. Plot size was 152 cm×518 cm.Each plot had approximately 50 plants.

NP2171 differs from A619 for several different traits described asfollows:

The silk emergence for the variety NP2171 is earlier at 1261.5 heatunits as compared to A619 at 1359.8 heat units. The days from emergenceto 50% silk is less for NP2171 than A619 at 63 days as compared to 68.

The heat units to 90% pollen shed for NP2171 is 1316.7 as compared to1363.8 for A619. The pollen shed duration from 10% to 90% is shorter forNP2171 than A619. Heat units from 10% to 90% shed for NP2171 is 80.3 and130.0 for A619.

The plant appearance of NP2171 differs significantly from A619. Thelength of the top ear internode of NP2171 is shorter at 12.4 cm thanA619 at 13.8 cm. The anthocyanic pigmentation of the brace roots israted a “3” or “moderate” for NP2171 and “2” or “faint” for A619. TheNP2171 ear node leaf is longer than the A619 leaf at 76.9 cm as comparedto 62.5 cm. The leaf sheath pubescence rating of NP2171 is “4” and A619is “2”. NP2171 also has a darker leaf color at 03 or “dark green”(Munsell Color—5GY 4/4) than A619, which is 02 or “medium green”(Munsell Color Value of 5GY 5/4).

Some of the more pronounced differences between NP2171 and A619 occur inthe tassel. The NP2171 tassel has fewer primary branches with 6 ascompared to 8 on A619. The anther color of NP2171 is 17 or purple(Munsell Color—5RP 5/4) and A619 is 05 or green-yellow (MunsellColor—5GY 8/6). The glume color of NP2171 is 05 or green-yellow (MunsellColor—2.5GY 7/6) and 05 or green-yellow with 16 or pale purple shade(Munsell Color—5RP 6/4). The glume color of A619 is 05 or green-yellow(Munsell Color—5GY 7/6) with a small percentage of 05 or green-yellowwith 16 or pale purple shade (Munsell Color—5RP 6/4). The glume colorbars of NP2167 are shaded 17 or purple. The A619 glume color bars arelight green with some shaded 16 or pale purple. There are some purple“tips” to the NP2171 glume.

The silk color of NP2171 is 05 or green-yellow (Munsell Color—2.5GY 8/8)with 16 or pale purple shaded ends. The A619 silk is 05 or green-yellow(Munsell Color—2.5GY 8/8).

The husk tightness of NP2171 is rated a “3”, 65 days after 50% silk ascompared to A619, which is rated a “4”.

The kernel row alignment of the NP2171 ear has a rating of “2” or“slightly curved” and A619 is rated a “1” or “straight”.

NP2171 has a “slight” ear taper, rated a “1”, while A619 is “average”and is rated as a “2”. NP2171 has a smaller cob diameter at themid-point than A619. The NP2171 cob is 25.0 mm while the A619 cob is27.1 mm.

The kernels of the two inbreds differ greatly. NP2171 has a longerkernel than A619. NP2171 is 10.8 mm long as compared to 10.0 mm on A619.The aleurone color of the NP2171 kernel appears to have a slight reddishshade while A619 is white.

The disease and insect resistance of the two inbreds also has somesignificant differences. The Common Rust rating of NP2171 is a “7” ascompared to a “6” for A619. The Grey Leaf Spot rating for NP2171 is a“5” and “3” for A619. The Northern Corn Leaf Blight Rating (MixedInoculum) is a “3” and A619 is a “4”. The First Brood European CornBorer rating of NP2171 is a “7” and A619 a “5”.

Origin and Breeding History of Corn Inbred Line NP2171 is described asfollows:

Inbred corn line NP2171 was derived from the cross of inbred line H8540and inbred line NP911. Both H8540 and NP911 were developed and are ownedby Syngenta Seeds, Inc. After development of the S₀ (or F₂) populationof H8540×NP911 the breeding method was simple pedigree ear-to-rowdevelopment of inbred NP2171.

The details of the development of inbred line NP2171 are as follows:

1988 Kauai, Hi.: Crossed H8540 by NP911 male to produce F₁ seed.

1989 Stanton, Minn.: Plants of the F₁ seed were self-pollinated toproduce the F₂ (S₀).

1990 Stanton, Minn.: Plants of the F₂ (S₀) were self-pollinated toproduce the S₁ generation. One hundred four S₁ ears were selected fromindividual F2 (S₀) plants based upon plant quality, root strength, earsize, and resistance to diseases.

1991 Stanton, Minn. Ear rows of the one hundred four selected S₁families were grown, observed, and self-pollinated to produce the S₂generation. Phenotypic selection of these S₁ families was based uponplant quality, synchrony of pollen shed and silk emergence, rootstrength, ear size, and resistance to disease. Testcross pollinations ofthe S₁ families were also made.

1992 Stanton, Minn. Ear rows of the selected S₂ families were grown,observed, and self-pollinated to produce the S₃ generation. Selection ofthe S₂ families was based upon performance of the S₁ testcrosses forgrain yield, maturity, and general quality. These testcrosses were grownat several locations. Phenotypic selection of the S₂ families was basedupon plant quality, synchrony of pollen shed and silk emergence, rootstrength, ear size, and resistance to disease. Testcrosses of the S₂families were also made.

1992 Kauai, Hi. Ear rows of the selected S₃ families were grown,observed and self-pollinated to produce the S₄ generation. Phenotypicselection of the S₃ families was based upon plant quality, synchrony ofpollen shed and silk emergence, root strength, ear size, and resistanceto disease.

1993 Stanton, Minn. Ear rows of the selected S₄ families were grown,observed and self-pollinated to produce the S₅ generation. Phenotypicselection of the S₄ families was based upon synchrony of pollen shed andsilk emergence, root strength, ear size, and resistance to disease.Testcrosses of the S₄ families were also made.

1993 Kauai, Hi. Ear rows of the selected S₅ families were grown,observed, and self-pollinated to produce the S₆ generation. Phenotypicselection of the S₅ families was based upon synchrony of pollen shed andsilk emergence, root strength, ear size, and resistance to disease.

1994 Stanton, Minn. Ear rows of each selected S₆ family were grown,observed and self-pollinated to produce individual S₇ ears. Selection ofthe S₆ families was based upon performance of the S₄ testcrosses forgrain yield, maturity, and general quality. These testcrosses were grownat several locations. Phenotypic selection of the S₆ families was basedupon synchrony of pollen shed and silk emergence, root strength, earsize, resistance to disease.

1994 Kauai, Hi. Ear rows of each selected S₇ family were grown, observedand self-pollinated to produce individual S₈ ears. Phenotypic selectionof the S₇ families was based upon synchrony of pollen shed and silkemergence, root strength, ear size, resistance to disease. Testcrossesof the S₇ families were also made.

1995 Stanton, Minn. Rows of each selected S₈ individual ear culture weregrown, observed and pollinated to produce S₉ ears or “Pre-Breeders”seed. Selection of the S₈ families was based upon performance of the S₇testcrosses for grain yield, maturity, and general quality. Thesetestcrosses were grown at several locations. The S₈ families wereclosely evaluated and selected for uniformity of anther and silk color,plant and ear height, and other characteristics. S₉ individual ears weresaved from one S₈ individual ear family.

1996 Stanton, Minn. Rows of a selected S₉ individual ear culture weregrown, observed and self-pollinated to produce S₁₀ or “Breeder Seed”.Plants were closely evaluated for uniformity of anther and silk color,plant and ear height, and other characteristics. Isozyme testingconfirmed the purity of this inbred line. The S₁₀ individual ears weresaved from one S₉ individual ear family.

1996 Chile Rows of a selected S₁₀ or “Breeder's Seed” were grown,observed and self pollinated to produce S₁₁ or additional “Breeder'sSeed”. Plants were closely evaluated for uniformity of anther and silkcolor, plant and ear height, and other characteristics. Isozyme testing(12 compounds) confirmed the purity of this inbred line. The S₁₁individual ears were saved from one S₁₀ individual ear family.

From 1994 to the present this inbred line has been observed in Stanton,Minn. and other locations. No phenotypic or isozymic variants have beenobserved. The variety NP2171 has been uniform and stable.

The invention also encompasses plants of inbred maize line NP2171 andparts thereof further comprising one or more specific, single genetraits which have been introgressed into inbred maize line NP2171 fromanother maize line. Preferably, one or more new traits are transferredto inbred maize line NP2171, or, alternatively, one or more traits ofinbred maize line NP2171 are altered or substituted. The transfer (orintrogression) of the trait(s) into inbred maize line NP2171 is forexample achieved by recurrent selection breeding, for example bybackcrossing. In this case, inbred maize line NP2171 (the recurrentparent) is first crossed to a donor inbred (the non-recurrent parent)that carries the appropriate gene(s) for the trait(s) in question. Theprogeny of this cross is then mated back to the recurrent parentfollowed by selection in the resultant progeny for the desired trait(s)to be transferred from the non-recurrent parent. After three, preferablyfour, more preferably five or more generations of backcrosses with therecurrent parent with selection for the desired trait(s), the progenywill be heterozygous for loci controlling the trait(s) beingtransferred, but will be like the recurrent parent for most or almostall other genes (see, for example, Poehlman & Sleper (1995) BreedingField Crops, 4th Ed., 172-175; Fehr (1987) Principles of CultivarDevelopment, Vol. 1: Theory and Technique, 360-376).

The laboratory-based techniques described above, in particular RFLP andSSR, are routinely used in such backcrosses to identify the progenieshaving the highest degree of genetic identity with the recurrent parent.This permits to accelerate the production of inbred maize lines havingat least 90%, preferably at least 95%, more preferably at least 99%genetic identity with the recurrent parent, yet more preferablygenetically identical to the recurrent parent, and further comprisingthe trait(s) introgressed from the donor patent. Such determination ofgenetic identity is based on molecular markers used in thelaboratory-based techniques described above. Such molecular markers arefor example those known in the art and described in Boppenmaier, et al.,“Comparisons among strains of inbreds for RFLPs”, Maize GeneticsCooperative Newsletter (1991) 65, pg. 90, or those available from theUniversity of Missouri database and the Brookhaven laboratory database.The last backcross generation is then selfed to give pure breedingprogeny for the gene(s) being transferred. The resulting plants haveessentially all of the morphological and physiological characteristicsof inbred maize line NP2171, in addition to the single gene trait(s)transferred to the inbred. Preferably, the resulting plants have all ofthe morphological and physiological characteristics of inbred maize lineNP2171, in addition to the single gene trait(s) transferred to theinbred. The exact backcrossing protocol will depend on the trait beingaltered to determine an appropriate testing protocol. Althoughbackcrossing methods are simplified when the trait being transferred isa dominant allele, a recessive allele may also be transferred. In thisinstance it may be necessary to introduce a test of the progeny todetermine if the desired trait has been successfull transferred.

Many traits have been identified that are not regularly selected for inthe development of a new inbred but that can be improved by backcrossingtechniques or genetic transformation. Examples of traits transferred toinbred maize line NP2171 include, but are not limited to, waxy starch,herbicide tolerance, resistance for bacterial, fungal, or viral disease,insect resistance, enhanced nutritional quality, improved performance inan industrial process, altered reproductive capability, such as malesterility or male fertility, yield stability and yield enhancement.Other traits transferred to inbred maize line NP2171 are for theproduction of commercially valuable enzymes or metabolites in plants ofinbred maize line NP2171.

Traits transferred to maize inbred line NP2171 are naturally occurringmaize traits, which are preferably introgressed into inbred maize lineNP2171 by breeding methods such as backcrossing, or are heterologoustransgenes, which are preferably first introduced into a maize line bygenetic transformation using genetic engineering and transformationtechniques well known in the art, and then introgressed into inbred lineNP2171. Alternatively a heterologous trait is directly introduced intoinbred maize line NP2171 by genetic transformation. Heterologous, asused herein, means of different natural origin or represents anon-natural state. For example, if a host cell is transformed with anucleotide sequence derived from another organism, particularly fromanother species, that nucleotide sequence is heterologous with respectto that host cell and also with respect to descendants of the host cellwhich carry that gene. Similarly, heterologous refers to a nucleotidesequence derived from and inserted into the same natural, original celltype, but which is present in a non-natural state, e.g. a different copynumber, or under the control of different regulatory sequences. Atransforming nucleotide sequence may comprise a heterologous codingsequence, or heterologous regulatory sequences. Alternatively, thetransforming nucleotide sequence may be completely heterologous or maycomprise any possible combination of heterologous and endogenous nucleicacid sequences.

A transgene introgressed into maize inbred line NP2171 typicallycomprises a nucleotide sequence whose expression is responsible orcontributes to the trait under the control of a promoter appropriate forthe expression of the nucleotide sequence at the desired time in thedesired tissue or part of the plant. Constitutive or inducible promotersare used. The transgene may also comprise other regulatory elements suchas for example translation enhancers or termination signals. In apreferred embodiment, the nucleotide sequence is the coding sequence ofa gene and is transcribed and translated into a protein. In anotherpreferred embodiment, the nucleotide sequence encodes an antisense RNA,a sense RNA that is not translated or only partially translated, at-RNA, a r-RNA or a sn-RNA.

Where more than one trait are introgressed into inbred maize lineNP2171, it is preferred that the specific genes are all located at thesame genomic locus in the donor, non-recurrent parent, preferably, inthe case of transgenes, as part of a single DNA construct integratedinto the donor's genome. Alternatively, if the genes are located atdifferent genomic loci in the donor, non-recurrent parent, backcrossingallows to recover all of the morphological and physiologicalcharacteristics of inbred maize line NP2171 in addition to the multiplegenes in the resulting maize inbred line.

The genes responsible for a specific, single gene trait are generallyinherited through the nucleus. Known exceptions are, e.g. the genes formale sterility, some of which are inherited cytoplasmically, but stillact as single gene traits. In a preferred embodiment, a heterologoustransgene to be transferred to maize inbred line NP2171 is integratedinto the nuclear genome of the donor, non-recurrent parent. In anotherpreferred embodiment, a heterologous transgene to be transferred to intomaize inbred line NP2171 is integrated into the plastid genome of thedonor, non-recurrent parent. In a preferred embodiment, a plastidtransgene comprises one gene transcribed from a single promoter or twoor more genes transcribed from a single promoter.

In a preferred embodiment, a transgene whose expression results orcontributes to a desired trait to be transferred to maize inbred lineNP2171 comprises a virus resistance trait such as, for example, a MDMVstrain B coat protein gene whose expression confers resistance to mixedinfections of maize dwarf mosaic virus and maize chlorotic mottle virusin transgenic maize plants (Murry et al. Biotechnology (1993)11:1559-64). In another preferred embodiment, a transgene comprises agene encoding an insecticidal protein, such as, for example, a crystalprotein of Bacillus thuringiensis or a vegetative insecticidal proteinfrom Bacillus cereus, such as VIP3 (see for example Estruch et al. NatBiotechnol (1997) 15:137-41). In a preferred embodiment, an insecticidalgene introduced into maize inbred line NP2171 is a Cry1Ab gene or aportion thereof, for example introgressed into maize inbred line NP2171from a maize line comprising a Bt-11 event as described in U.S. Pat. No.6,114,608, which is incorporated herein by reference, or from a maizeline comprising a 176 event as described in Koziel et al. (1993)Biotechnology 11: 194-200. In yet another preferred embodiment, atransgene introgressed into maize inbred line NP2171 comprises aherbicide tolerance gene. For example, expression of an alteredacetohydroxyacid synthase (AHAS) enzyme confers upon plants tolerance tovarious imidazolinone or sulfonamide herbicides (U.S. Pat. No.4,761,373). In another preferred embodiment, a non-transgenic traitconferring tolerance to imidazolinones is introgressed into maize inbredline NP2171 (e.g a “IT” or “IR” trait). U.S. Pat. No. 4,975,374,incorporated herein by reference, relates to plant cells and plantscontaining a gene encoding a mutant glutamine synthetase (GS) resistantto inhibition by herbicides that are known to inhibit GS, e.g.phosphinothricin and methionine sulfoximine. Also, expression of aStreptomyces bar gene encoding a phosphinothricin acetyl transferase inmaize plants results in tolerance to the herbicide phosphinothricin orglufosinate (U.S. Pat. No. 5,489,520). U.S. Pat. No. 5,013,659, which isincorporated herein by reference, is directed to plants that express amutant acetolactate synthase (ALS) that renders the plants resistant toinhibition by sulfonylurea herbicides. U.S. Pat. No. 5,162,602 disclosesplants tolerant to inhibition by cyclohexanedione andaryloxyphenoxypropanoic acid herbicides. The tolerance is conferred byan altered acetyl coenzyme. A carboxylase(ACCase). U.S. Pat. No.5,554,798 discloses transgenic glyphosate tolerant maize plants, whichtolerance is conferred by an altered 5-enolpyruvyl-3-phosphoshikimate(EPSP) synthase gene. U.S. Pat. No. 5,804,425 discloses transgenicglyphosate tolerant maize plants, which tolerance is conferred by anEPSP synthase gene derived from Agrobacterium tumefaciens CP-4 strain.Also, tolerance to a protoporphyrinogen oxidase inhibitor is achieved byexpression of a tolerant protoporphyrinogen oxidase enzyme in plants(U.S. Pat. No. 5,767,373). Another trait transferred to inbred maizeline NP2171 confers tolerance to an inhibitor of the enzymehydroxyphenylpyruvate dioxygenase (HPPD) and transgenes conferring suchtrait are, for example, described in WO 9638567, WO 9802562, WO 9923886,WO 9925842, WO 9749816, WO 9804685 and WO 9904021. All issued patentsreferred to herein are, in their entirety, expressly incorporated hereinby reference.

In a preferred embodiment, a transgene transferred to maize inbred lineNP2171 comprises a gene conferring tolerance to a herbicide and at leastanother nucleotide sequence encoding another trait, such as for example,an insecticidal protein. Such combination of single gene traits is forexample a Cry1Ab gene and a bar gene.

Specific transgenic events introgressed into maize inbred line NP2171can be obtained through the list of Petitions of Nonregulated StatusGranted by APHIS as of Oct. 12, 2000. For example, introgressed fromglyphosate tolerant event GA21 (9709901p), glyphosatetolerant/Lepidopteran insect resistant event MON 802 (9631701p),Lepidopteran insect resistant event DBT418 (9629101p), male sterileevent MS3 (9522801p), Lepidopteran insect resistant event Bt11(9519501p), phosphinothricin tolerant event B16 (9514501p), Lepidopteraninsect resistant event MON 80100 (9509301p), phosphinothricin tolerantevents T14, T25 (9435701p), Lepidopteran insect resistant event176(9431901p).

The introgression of a Bt11 event into a maize line, such as maizeinbred line NP2171, by backcrossing is exemplified in U.S. Pat. No.6,114,608, and the present invention is directed to methods ofintrogressing a Bt11 event into maize inbred line NP2171 using forexample the markers described in U.S. Pat. No. 6,114,608 and toresulting maize lines.

Direct selection may be applied where the trait acts as a dominanttrait. An example of a dominant trait is herbicide tolerance. For thisselection process, the progeny of the initial cross are sprayed with theherbicide prior to the backcrossing. The spraying eliminates any plantwhich do not have the desired herbicide tolerance characteristic, andonly those plants that have the herbicide tolerance gene are used in thesubsequent backcross. This process is then repeated for the additionalbackcross generations.

This invention also is directed to methods for producing a maize plantby crossing a first parent maize plant with a second parent maize plantwherein either the first or second parent maize plant is a maize plantof inbred line NP2171 or a maize plant of inbred line NP2171 furthercomprising one or more single gene traits. Further, both first andsecond parent maize plants can come from the inbred maize line NP2171 oran inbred maize plant of NP2171 further comprising one or more singlegene traits. Thus, any such methods using the inbred maize line NP2171or an inbred maize plant of NP2171 further comprising one or more singlegene traits are part of this invention: selfing, backcrosses, hybridproduction, crosses to populations, and the like. All plants producedusing inbred maize line NP2171 or inbred maize plants of NP2171 furthercomprising one or more single gene traits as a parent are within thescope of this invention. Advantageously, inbred maize line NP2171 orinbred maize plants of NP2171 further comprising one or more single genetraits are used in crosses with other, different, maize inbreds toproduce first generation (F1) maize hybrid seeds and plants withsuperior characteristics.

In a preferred embodiment, seeds of inbred maize line NP2171 or seeds ofinbred maize plants of NP2171 further comprising one or more single genetraits are provided as an essentially homogeneous population of inbredcorn seeds. Essentially homogeneous populations of inbred seed are thosethat consist essentially of the particular inbred seed, and aregenerally purified free from substantial numbers of other seed, so thatthe inbred seed forms between about 90% and about 100% of the totalseed, and preferably, between about 95% and about 100% of the totalseed. Most preferably, an essentially homogeneous population of inbredcorn seed will contain between about 98.5%, 99%, 99.5% and about 100% ofinbred seed, as measured by seed grow outs. The population of inbredcorn seeds of the invention is further particularly defined as beingessentially free from hybrid seed. The inbred seed population may beseparately grown to provide an essentially homogeneous population ofplants of inbred maize line NP2171 or inbred maize plants of NP2171further comprising one or more single gene traits.

As used herein, the term “plant” includes plant cells, plantprotoplasts, plant cell tissue cultures from which maize plants can beregenerated, plant calli, plant clumps, and plant cells that are intactin plants or parts of plants, such as embryos, pollen, ovules, flowers,kernels, ears, cobs, leaves, husks, stalks, roots, root tips, anthers,silk, seeds and the like.

Duncan, Williams, Zehr, and Widholm, Planta (1985) 165:322-332 reflectsthat 97% of the plants cultured that produced callus were capable ofplant regeneration. Subsequent experiments with both inbreds and hybridsproduced 91% regenerable callus that produced plants. In a further studyin 1988, Songstad, Duncan & Widholm in Plant Cell Reports (1988),7:262-265 reports several media additions that enhance regenerability ofcallus of two inbred lines. Other published reports also indicated that“nontraditional” tissues are capable of producing somatic embryogenesisand plant regeneration. K. P. Rao, et al., Maize Genetics CooperationNewsletter, 60:64-65 (1986), refers to somatic embryogenesis from glumecallus cultures and B. V. Conger, et al., Plant Cell Reports, 6:345-347(1987) indicates somatic embryogenesis from the tissue cultures of maizeleaf segments. Thus, it is clear from the literature that the state ofthe art is such that these methods of obtaining plants are, and were,“conventional” in the sense that they are routinely used and have a veryhigh rate of success.

Tissue culture procedures of maize are described in Green and Rhodes,“Plant Regeneration in Tissue Culture of Maize,” Maize for BiologicalResearch (Plant Molecular Biology Association, Charlottesville, Va.1982, at 367-372) and in Duncan, et al., “The Production of CallusCapable of Plant Regeneration from Immature Embryos of Numerous Zea maysGenotypes,” 165 Planta 322-332 (1985). Thus, another aspect of thisinvention is to provide cells that upon growth and differentiationproduce maize plants having the physiological and morphologicalcharacteristics of inbred maize line NP2171. In a preferred embodiment,cells of inbred maize line NP2171 are transformed genetically, forexample with one or more genes described above, for example by using atransformation method described in U.S. Pat. No. 6,114,608, andtransgenic plants of inbred maize line NP2171 are obtained and used forthe production of hybrid maize plants.

Maize is used as human food, livestock feed, and as raw material inindustry. The food uses of maize, in addition to human consumption ofmaize kernels, include both products of dry- and wet-milling industries.The principal products of maize dry milling are grits, meal and flour.The maize wet-milling industry can provide maize starch, maize syrups,and dextrose for food use. Maize oil is recovered from maize germ, whichis a by-product of both dry- and wet-milling industries.

Maize, including both grain and non-grain portions of the plant, is alsoused extensively as livestock feed, primarily for beef cattle, dairycattle, hogs, and poultry. Industrial uses of maize include productionof ethanol, maize starch in the wet-milling industry and maize flour inthe dry-milling industry. The industrial applications of maize starchand flour are based on functional properties, such as viscosity, filmformation, adhesive properties, and ability to suspend particles. Themaize starch and flour have application in the paper and textileindustries. Other industrial uses include applications in adhesives,building materials, foundry binders, laundry starches, explosives,oil-well muds, and other mining applications. Plant parts other than thegrain of maize are also used in industry: for example, stalks and husksare made into paper and wallboard and cobs are used for fuel and to makecharcoal.

The seed of inbred maize line NP2171 or of inbred maize line NP2171further comprising one or more single gene traits, the plant producedfrom the inbred seed, the hybrid maize plant produced from the crossingof the inbred, hybrid seed, and various parts of the hybrid maize plantcan be utilized for human food, livestock feed, and as a raw material inindustry.

The present invention therefore also discloses an agricultural productcomprising a plant of the present invention or derived from a plant ofthe present invention. The present invention also discloses anindustrial product comprising a plant of the present invention orderived from a plant of the present invention. The present inventionfurther discloses methods of producing an agricultural or industrialproduct comprising planting seeds of the present invention, growingplant from such seeds, harvesting the plants and processing them toobtain an agricultural or industrial product.

DEPOSIT

Applicants have made a deposit of at least 2500 seeds of Inbred MaizeLine NP2171 with the American Type Culture Collection (ATCC), Manassas,Va., 20110-2209 U.S.A., ATCC Deposit No: PTA-2886. This deposit of theInbred Maize Line NP2171 will be maintained in the ATCC depository,which is a public depository, for a period of 30 years, or 5 years afterthe most recent request, or for the effective life of the patent,whichever is longer, and will be replaced if it becomes nonviable duringthat period. Additionally, Applicants have satisfied all therequirements of 37 C.F.R. §§1.801-1.809, including providing anindication of the viability of the sample. Applicants impose norestrictions on the availability of the deposited material from theATCC; however, Applicants have no authority to waive any restrictionsimposed by law on the transfer of biological material or itstransportation in commerce. Applicants do not waive any infringement ofits rights granted under this patent or under the Plant VarietyProtection Act (7 USC 2321 et seq.).

The foregoing invention has been described in detail by way ofillustration and example for purposes of clarity and understanding.However, it will be obvious that certain changes and modifications suchas single gene modifications and mutations, somaclonal variants, variantindividuals selected from large populations of the plants of the instantinbred and the like may be practiced within the scope of the invention,as limited only by the scope of the appended claims.

What is claimed is:
 1. Seed of maize inbred line designated NP2171representative seed of said maize inbred line having been depositedunder ATCC Accession No: PTA-2886.
 2. A maize plant, or a part thereof,produced by growing the seed of claim
 1. 3. Pollen of the plant of claim2.
 4. An ovule of the plant of claim
 2. 5. A maize plant, or a partthereof, having all the physiological and morphological characteristicsof a plant according to claim
 2. 6. A maize plant or a part thereofproduced from the maize plant according to claim 2 or 5, bytransformation with a transgene that confers upon said maize plant or apart thereof tolerance to an herbicide.
 7. The maize plant according toclaim 6, wherein said herbicide is glyphosate, gluphosinate, asulfonylurea herbicide, an imidazolinone herbicide, ahydroxyphenylpyruvate dioxygenase inhibitor or a protoporphyrinogenoxidase inhibitor.
 8. A maize plant or a part thereof produced from themaize according to claim 2 or 5, by transformation with an expressionvector comprising a transgene that confers upon said maize plant or apart thereof insect resistance, disease resistance or virus resistance.9. The maize plant according to claim 8, wherein said transgene is aBacillus thuringiensis Cry1Ab gene.
 10. The maize plant according toclaim 9, wherein said expression vector further comprises a bar gene.11. Seed produced by selfing the plant according to claim 2 or 5,wherein said seed produce plants having all the physiological andmorphological characteristics of inbred line NP2171, seed of said inbredline having been deposited under ATCC Accession No: PTA-2886.
 12. Atissue culture of regenerable cells of the maize plant according toclaim
 2. 13. The tissue culture according to claim 12, wherein theregenerable cells are from a tissue selected fronm the group consistingof embryo, meristem, pollen, leaf, anther, root, root tip, silk, flower,kernel, ear, cob, husk and stalk.
 14. A maize plant regenerated from thetissue culture of claim 12, wherein the regenerated plant has all themorphological and physiological characteristics of inbred line NP2171,seed of said inbred line having bee deposited under ATCC Accession No:PTA-2886.
 15. A method for producing maize seed comprising crossing afirst parent maize plant with a second parent maize plant and harvestingthe resultant maize seed, wherein said first or second parent maizeplant is the inbred maize plant of claim 2 or
 5. 16. The methodaccording to claim 15, wherein said resultant seed is a hybrid maizeseed.
 17. The method according to claim 15, wherein the inbred maizeplant is the female parent.
 18. The method according to claim 15,wherein the inbred maize plant is the male parent.
 19. A method ofintroducing a desired trait into maize inbred line NP2171 comprising: a)crosing NP2171 plants grown from seed deposited under ATCC Accession No.PTA-2886, with plants of another maize line that comprise a desiredtrait to produce F1 progeny plants, wherein the desired trait isselected from male sterility, herbicide resistance, insect resistance,and resisitance to bacterial, fungal or viral disease; (b) selecting F1progeny plants that have the desired trait to produce seleced F1 progenyplants; (c) crossing the selected progeny plants with NP2171 plants toproduce backcross progeny plants; (d) selecting for backcross progenyplants that have the desired trait and physiological and morphologicalcharacteristics of maize inbred line NP2171 to produce selectedbackcross progeny plants; and (e) repeating steps (c) and (d) three ormore times in succession to produce selected fourth or higher backcrossprogeny plants that comprise the desired trait and all of thephysiological and morphological characteristics of maize inbred lineNP2171 listed in Table 1 as determined at the 5% significance level whengrown in the same environmental conditions.
 20. A plant produced by themethod of claim 19, wherein the plant has the desired trait and all ofthe physiological and morphological characteristics of corn inbred lineNP2171 listed in Table 1 as determined at the 5% significance level whengrow in the same environmental conditions.